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Abstract:
To study age-related strategy differences during encoding, we
recorded ERPs from young and old adults as they encoded real words
and pseudowords. In the first encoding condition, they performed a
lexical decision task, classifying each item according to whether
it was a real word or pseudoword. In the second encoding condition
with a new set of items, they performed the same lexical decision
task, but were told that recognition memory for those items would
be tested later. ERPs recorded from left and right scalp locations
were compared for the two encoding conditions. The lateral
asymmetry of the P300 component (~550 msec) was affected by
encoding condition in the elderly (p=.02) but not the young
(p=.78). When the elderly were encoding for memory, P300 tended to
have a left>right distribution, compared to a right>left
distribution when not encoding for memory. Greater left>right
asymmetry was associated with worse performance on the subsequent
recognition test in young subjects (r=-0.62, p=.04) and tended to
be so for the elderly (r=-0.74, p=.06). This suggests the
left>right asymmetry seen in the elderly during memory encoding
is not an effective strategy and may be related to memory failures
in the elderly.
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